The present invention relates to a transcutaneous energy transfer (TET) system, and more particularly to a device for transferring or relaying power wirelessly within a TET system, as well methods of operating the system and/or device.
TET systems are used to supply power to devices such as pumps implanted internally within the human body. An electromagnetic field generated by a transmitting coil outside the body can transmit power across a cutaneous (skin) barrier to a magnetic receiving coil implanted within the body. The receiving coil can then transfer the received power to the implanted pump or other internal device and to one or more batteries implanted within the body to charge the battery.
One of the challenges presented by TET systems is to provide sufficient power to the internal device to enable continuous operation of the internal device. For this purpose, the TET system may include an implanted battery that stores power for operating the internal device. However, the implanted battery's supply is limited and may need to be recharged frequently. The TET system may also, or alternatively, include an external TET power unit to supply the internal device's entire power demand. However, the external TET power unit also has a limited supply and may need to be recharged regularly. Moreover, some activities such as showering or swimming may preclude wearing the external TET power unit.
Constant recharging of an external TET power unit, as well as an implanted battery is an inconvenience for a user with the internal device(s). Ordinarily, the external TET power unit must be plugged into a charging station in order to be recharged. A user may have to wait for the unit to sufficiently charge before wearing the unit. Alternatively, the user may replace the battery in the external TET power unit with a fully charged battery.
It is therefore desirable to improve upon present TET systems to make recharging of external TET power units and implanted batteries more convenient for the user.